AeroShell 15w-50, Lycoming 0-540, Piper Pa28

[wings&wheels]

Here is the past few oil analyses on our bird. There aren't too many aircraft posts here so I thought this would be interesting.

Engine is a 540 ci, horizontally opposed, air & oil cooled 6 cylinder, 235 hp w/ a constant speed propeller (controlled by engine oil presssure through a governor)and uses 100 octane leaded av fuel. Engine has approx 300 hours left until overhaul. Copper is a bit elevated for the last 2 samples, but the other metals look fine so we suspect that it is due to inactvity during a wet Spring and Summer. Also, the prop was overhauled last year so that could account for the high copper, a bushing maybe, or it could be a coincidence. Overall we're happy w/ the results, watching the copper though.

hf=hours flown

hf 17 24 23 20 28 19 Univ avg
Al 03 03 03 03 03 03 06
Cr 02 03 04 04 03 04 04
Fe 12 12 14 14 15 13 26
Cu 08 07 04 02 03 02 05
Pb 2211/3027/2923/2085/2569/2145/3860
Ni 00 01 00 00 01 00 02
Sn 00 00 02 01 00 01 01
Si 04 05 05 05 04 05 06
Ca 02 01 01 00 01 01 05
Mg 04 04 06 06 08 05 03
Ph 1076/1140/998/912/1103/1060
Zn 01 02 02 01 01 02 03

All others 0

Vis 89.8

Fuel & H2O <1%

 

[Gene K]

I dont know anything about aircraft.

However the lack of calcium and very high lead is interesting.

Is the lead antimony?

 

[Pablo]

Leaded fuel. No Zn. No Ca. Stinking interesting to me.

 

[Gene K]

Quote:

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Leaded fuel.

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Dohhhh....

 

[V1]

Cool. I've never seen such a thorough UOA history for an airplane before. It seems much better than I would imagine. Is your plane used just as a cross-country machine, or does it take some abuse?

This summer I got to look inside an O-540 that was on a 182. The engine was being replaced even though it had several hundred hours before its overhaul. Both cam and crankshaft were pitted from corrosion due to lack of use.

So this is a carbureted 540? What manifold pressure/RPM combinations do you use during cruise? How lean do you run the mixture EGT wise?

I frequently fly an Aztec with IO-540's. We often speculate whether it's better to run them near peak EGT or rich of peak. Plenty of debate there.

Thanks for showing.

 

[Quickbeam]

UOA is quite common in aviation. Been done for decades. W&W, are the jugs on their first run? If not are they channel chrome? What's the consumption?

VI, does the Aztec have an engine analyzer like a GEM or JPI? If so and since those 504s are injected you should run them lean of peak. Try 100 or so degrees LOP. The engines will run cooler, cleaner, and economy will increase with only a minor loss of airspeed. Better still is to get the owner to spring for a set of GAMI injectors. They're worth every penny. I'd run those engines over-square too as long as vibration permits it.

 

[V1]

Aztec has standard engine monitoring setup. Mixtures are usually set at peak EGT (1225 to 1250F). The mechanic says both engines are very clean.

 

[wings&wheels]

The engine is on its original Lycoming cylinders, it is a factory overahul unit. It uses 1 qt every 7-10 hours, compressions are all above 73/80. The airplane is usually flown on short cross country flights, coffee & burger runs and an occasional Angel Flight around the region. It isn't used for training except for my currency work.

I fly it 50dg rich of peak using one of the slightly over-square settings on the table, typically I am at 2300rpm & 23.3in/hg at 2,500 or 3,500 ft for local flights.

Interesting point about vibration as I've noticed that this engine has certain power settings that just don't sound well and cause a vibration on the cowling...I avoid those. Yet others are as smooth as glass..well as smooth as a big Lycoming gets.

Anyone have any thoughts on the increased copper given the other wear metals?

 

[ARB1977]

Quote:

---

Here is the past few oil analyses on our bird. There aren't too many aircraft posts here so I thought this would be interesting.

Engine is a 540 ci, horizontally opposed, air & oil cooled 6 cylinder, 235 hp w/ a constant speed propeller (controlled by engine oil presssure through a governor)and uses 100 octane leaded av fuel. Engine has approx 300 hours left until overhaul. Copper is a bit elevated for the last 2 samples, but the other metals look fine so we suspect that it is due to inactvity during a wet Spring and Summer. Also, the prop was overhauled last year so that could account for the high copper, a bushing maybe, or it could be a coincidence. Overall we're happy w/ the results, watching the copper though.

hf=hours flown

hf 17 24 23 20 28 19 Univ avg
Al 03 03 03 03 03 03 06
Cr 02 03 04 04 03 04 04
Fe 12 12 14 14 15 13 26
Cu 08 07 04 02 03 02 05
Pb 2211/3027/2923/2085/2569/2145/3860
Ni 00 01 00 00 01 00 02
Sn 00 00 02 01 00 01 01
Si 04 05 05 05 04 05 06
Ca 02 01 01 00 01 01 05
Mg 04 04 06 06 08 05 03
Ph 1076/1140/998/912/1103/1060
Zn 01 02 02 01 01 02 03

All others 0

Vis 89.8

Fuel & H2O

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I used to work as a mechanic in GA and from what i saw Lycoming engines are built like the old school toyota engines, very reliable.

 

[Quickbeam]

W&W, your chrome is pretty low. It's why I asked if the jugs were nitrided or chrome. My IO-360 is also 300 from overhaul but the jugs are chrome and on their second run. I always run the engine over-square to keep consumption down to 1 qt/4 hrs and to reduce tach time. Been doing that for 1700 hours and no problems. Haven't had a cylinder off yet...knock on wood.

Best to run it at the sweet spot vibration wise. Mine is good across the rpm range (even though it's a 4 banger) since I had a dy-bal done on the prop, a Hartzell 3-blade. Lots of benefits besides a smoother ride so if you haven't had yours balanced you may want to look into it.

I run the engine 100-150 LOP at 75% unless I'm in a hurry but I have GAMI injectors. Imho the cost in fuel savings alone justifies them. They obviously can't be used on a carbed engine though. Your copper could be from a rocker shaft bushing. My used oil analysis numbers are decent too but I know the camshaft is worn. It's the lifter spalling thing Lycs are known for. You know used oil analysis won't catch camshaft spalling yes? You have to do good filter inspections.

Looks like we'll both be biting the overhaul bullet soon. Not a cheap proposition these days is it? I'll be doing my own to keep the cost down but since I'll be retiring the jugs and going with factory new ones it's still going to be spendy.

 

[JohnBrowning]

For the low hours on these oil changes I think they look great!Sitting in damp counditions is hard on an engine. When you take into acount that the rings are Fe and the jugs have cermmi-crome or simalar coating the numbers look great.

 

[Quickbeam]

He's got steel nitirded barrels so the rings are likely chrome. Last I heard Cermichrome is an old process that's been replaced by silicon carbide but yeah, it's corrosion that rusts steel jugs and it's the number one cause of lifter spalling. That and the cam is up top on Lycs with only splash lubrication. It's why something like 80-90% of Lycomings need new cams at overhaul. Still, we're talking about engines that run at either 100 or 75% power for years on end. Try doing that with a car motor and see how long it lasts

 

[JohnBrowning]

I worked on quite a few while I was in college. I major was Aerospace Technologies/Materials minor in Applied Science. Three year into my 4 year degree the school decided that my major was not a money maker any longer so I had to change majors. So I took 24-28 credit hours per semester my final year and graduated with a Business Degree with a Minor in Marketing. I spent a lot of free time at the airport working for the one of the A&P's I got to count it as my internship. I have always loved getting my hands dirty!!!

The flight school used to do 50 hour oil change intervals and ever 100 hours they did an anaul inspection for CYA reasons.